Traditionally, a wireless power transfer terminal used for both transmission and reception that can both receive and transmit power by wireless power transfer has been proposed. See, for example, Japanese Unexamined Patent Application Publication No. 2006-60910 (Patent Literature 1). Such a wireless power transfer terminal can be utilized as an auxiliary power source of an electronic device, such as a cellular phone terminal or a potable player, and in giving power to and receiving power from other electronic devices.
FIG. 1 is a circuit diagram of a traditional wireless power transfer terminal 101 to which Patent Literature 1 is refers. This wireless power transfer terminal 101 includes a coil 102 used for both transmitting and receiving power via a respective power transmission circuit 103 and a power reception circuit 104. The power transmission circuit 103 includes an inverter for converting an input voltage from, for example, a battery, into an alternating-current output. The coil 102 used, for both transmission and reception, transmits power to a partner device over an electromagnetic field excited in the coil 102 by application of an alternating-current output from the power transmission circuit 103, and receives power from the partner device over an electromagnetic field output from the partner device. The power reception circuit 104 includes a rectifier circuit for converting an alternating-current that has been excited (input) in the coil 102 into an output voltage.